U.S. Pat. No. 4,934,086 to Houde-Walter describes a recoil spring guide mounting for a laser sight. A laser sight for a firearm has a recoil spring guide. Components are mounted on the spring guide so that a light beam is directed along the axis of the spring guide. This automatically makes the light beam parallel with the barrel of the firearm.
U.S. Pat. No. 5,509,226 to Houde-Walter describes a laser sight having a power source disposed substantially entirely within the recoil spring guide chamber of a firearm, such as the recoil cavity of a pistol. The laser sight is itself contained in an elongated housing having at one end a window through which a laser beam is emitted and at the other end a battery cap.
U.S. Pat. No. 5,179,235 to Toole describes a laser sighting device for a pistol includes a universally mounted laser diode at the forward end of the pistol's trigger guard, wherein positioning of the laser beam is accomplished via adjustment screws from within the trigger guard. An energizing cable in the pistol structure is connected to a power supply located within the pistol's handgrip, and an externally operable activating switch is provided at the rear of the handgrip which is easily actuated by the user's hand immediately before the trigger is operated. The switch means is operable by pressure from the hand of the user between thumb and forefinger as the user's forefinger is inserted through the trigger guard.